1. Field of the Invention
The present invention generally relates to folding type portable radio machines and chassis of the radio machines, and more particularly, to a folding type portable radio machine, which is folded at the time of being carried and unfolded at the time of being used for telephone calling or communicating, and a chassis for the phone.
2. Description of the Related Art
A folding type portable radio machine such as a folding type portable phone, including a chassis for the phone, is folded at the time of being carried. The radio machine is unfolded at the time of being used for telephone calling or communicating, and if necessary an antenna installed inside thereof is extended externally.
FIG. 1 is an exploded perspective view of a related art folding type portable phone 10. Referring to FIG. 1, the related art folding type portable phone 10 includes a dial operations key side part 11 held by the hands of a user, a liquid crystal side part 12 which is folded and unfolded, a left hinge mechanism part 13a, a right hinge mechanism part 13b, and others.
The left hinge mechanism part 13a and the right hinge mechanism part 13b are respectively provided at left and right sides of the folding type portable phone 10 so as to connect the dial operations key side part 11 to the liquid crystal side part 12.
The dial operations key side part 11 is formed by combining a plate part 20 and a lower part housing 21. A lower part chassis 23 where a printed board module 22 is provided is installed inside of the dial operations key side part 11.
The liquid crystal side part 12 is formed by combing a plate part 30 and an upper housing 31. An upper part chassis 34 where a printed board module 32 is provided is installed inside of the liquid crystal side part 12.
The left hinge mechanism part 13a is covered with an arc part 23 projecting from an edge of the plate part 20 of the dial operations key side part 11. The right hinge mechanism part 13b is covered with an arc part 33 projecting from an edge of the plate part 30 of the liquid crystal side part 12.
Furthermore, the printed board module 22 of the dial operations key side part 11 and the printed board module 32 of the liquid crystal side part 12 are connected by a flexible printed board 40. The flexible printed board 40 forms a curl configuration at a designated position thereof. In addition, an antenna 45 is flexibly received in the lower part housing 21 of the dial operation key side part 11. A battery pack 46 is fitted on a lower surface of the lower part housing 21.
Meanwhile, the upper part chassis 34 and the lower part chassis 23 are molded articles which are made of resin and where metal is vaporized. Furthermore, metal is vaporized on both left hinge mechanism part 13a and the right hinge mechanism part 13b so that there is conductivity between the dial operation key side part 11 and the liquid crystal side part 12. Alternatively, metal is vaporized on neither left hinge mechanism part 13a nor the right hinge mechanism part 13b so that there is no conductivity between the dial operation key side part 11 and the liquid crystal side part 12.
FIG. 2 is a schematic view of the upper part chassis 34 and the lower part chassis 23 in a case where the related art folding type portable phone 10 is folded. More specifically, FIG. 2-(a) is a view seen in the X-Y plane of FIG. 1 and FIG. 2-(b) is a view seen in Y-Z plane of FIG. 1.
Referring to FIG. 1 and FIG. 2, when the folding type portable phone is carried, the upper housing 31 where the upper part chassis 34 is provided inside is closed against the lower housing 21 where the lower part chassis 23 is provided inside. In this case, as shown in FIG. 2, even if the antenna 45 is extended, the upper part chassis 34 is not an obstacle to transmission and receipt of the radio wave by the antenna 45.
For example, as shown in Japanese Laid-Open Patent Application No. 2002-246821, in a conventional antenna for portable communication terminals, when a plate antenna is held so as to be separated from a human body by 20 mm, the gain of the plate antenna can be made higher by 2.5 dB or more over the entire frequency band (1,920-2,170 MHz), than the gain of a half-wave length dipole antenna.
Furthermore, as shown in Japanese Laid-Open Patent Application No. 2000-216611, there is a conventional folding type mobile phone, wherein a monopole antenna is formed by first and second conductive films provided at first and second housings when the phone is unfolded, and the second conductive film acts like a grounding plane when the phone is folded.
As shown in Japanese Laid-Open Patent Application No. 11-317610, there is a conventional antenna of a folding type portable phone that functions as a monopole antenna in a normal operation state and as a slot antenna in a standby state.
Furthermore, as shown in Japanese Laid-Open Patent Application No. 2001-77623, there is a small-sized antenna in a stack structure with sufficient passing band width achieved by eliminating mutual interference by coupling a resonance structure, which has a high center frequency ratio on both sides of a coupling layer made of a planar conductive layer, with an external processing unit via a slit formed in the coupling layer.
However, in a case where the folding type portable phone 10 is unfolded and the antenna 45 is extended in order to conduct communications and telephone calling, there might be the following problems with regard to transmission and receipt of the radio wave.
FIG. 3 is a schematic view of the upper part chassis 34 and the lower part chassis 23 in a case where the related art folding type portable phone 10 is unfolded. More specifically, FIG. 3-(a) is a view seen in the X-Y plane of FIG. 1 and FIG. 3-(b) is a view seen in the Y-Z plane of FIG. 1.
Referring to FIG. 1 and FIG. 3, when the communicating or telephone calling is implemented, the upper housing 31 where the upper part chassis 34 is provided inside thereof is rotated against the lower housing 21 where the lower part chassis 23 is provided inside thereof so that the folding type portable phone 10 is unfolded and the antenna 45 is extended.
In this case, as shown in FIG. 3, the upper part chassis 34 is situated right at the side of the antenna 45. Hence, the upper part chassis 34 is an obstacle for the antenna 45 to transmit and receive the radio wave.
Therefore, the gain of the antenna 45 is degraded so that an radiation efficiency is reduced. Because of this, it may be difficult to implement a high quality telephone call or communications by the related art folding type portable phone 10.
Furthermore, the conventional portable radio machine such as the folding type portable phone 10 shown in FIG. 1 through FIG. 3 generally has an outside antenna such as a helical antenna or a monopole antenna, or an installed antenna such as chip antenna, a plate antenna, or a batch antenna.
In addition, in order to realize the portable radio machine being applied to Bluetooth or a radio LAN based on multi-functionalization of a recent communications developments, it is required for the portable radio machine to have antennas corresponding to respective frequencies of transmission.
Hence, spaces in which the respective antennas are to be provided is required in the portable radio machine. In addition, the folding portable radio machine is required to be further miniaturized and reduced in weight.
However, it is difficult for the related art portable radio machines to accomplish both multi-functionalization of the communications and miniaturization and weight savings of the radio machine.